Chaperones are the target in aloe-emodin-induced human lung nonsmall carcinoma H460 cell apoptosis

Advances in Understanding the Role of Aloe Emodin and Targeted Drug Delivery Systems in Cancer

Cancer is one of the important causes of death worldwide. Despite remarkable improvements in cancer research in the past few decades, several cancer patients still cannot be cured owing to the development of drug resistance. Natural sources might have prominence as potential drug candidates. Among the several chemical classes of natural products, anthraquinones are characterized by their large structural variety, noticeable biological activity, and low toxicity. Aloe emodin, an anthraquinone derivative, is a natural compound found in the roots and rhizomes of many plants. This compound has proven its antineoplastic, anti-inflammatory, antiangiogenic, and antiproliferative potential as well as ability to prevent cancer metastasis and potential in reversing multidrug resistance of cancer cells. The anticancer property of aloe emodin, a broad-spectrum inhibitory agent of cancer cells, has been detailed in many biological pathways. In cancer cells, these molecular mechanisms consist of inhibition of cell growth and proliferation, cell cycle arrest deterioration, initiation of apoptosis, antimetastasis, and antiangiogenic effect. In accordance with the strategy of developing potential drug candidates from natural products, aloe emodin's low bioavailability has been tried to be overcome by structural modifications and nanocarrier systems. Consequently, this review summarizes the antiproliferative and anticarcinogenic properties of aloe emodin, as well as the enhanced activity of its derivatives and the advantages of drug delivery systems on bioavailability.

Natural substances to potentiate canonical glioblastoma chemotherapy

Glioblastoma multiforme (GBM) is the most frequent primary malignant brain tumour prevalent in humans, that exhibits aggressive cell proliferation and rapid invasion of normal brain tissue. Despite aggressive therapeutic approaches consisting of maximum safe surgical resection followed by radio-chemotherapy with temozolomide (TMZ), more than 95% of GBM patients die within 5 years after diagnosis. In most cases, the therapy is not able to counteract the growth and invasiveness of the tumour, which relapses after an interval of time that varies from patient to patient. An increasing number of evidence indicates that natural substances exhibited effective anti-tumour functions and might be successfully used in the treatment of GBM. This review summarizes some natural substances: lactoferrin, hispolon, aloe-emodin and tea tree oil; all these show a growth inhibition and synergistic effect when together with TMZ, (the most commonly used alkylating drug for the treatment of glioblastoma) were administered to U87MG glioblastoma cell line in vitro and in murine animal model. U87MG cell growth was monitored by daily cell count after treatments with the substances mentioned above and growth analysis showed that all drugs significantly decrease proliferation of U87MG in a time- and dose-dependent manner. FACS analysis demonstrates a block of cell cycle in S, G2/M or G0/G1 phases. These substances mediate multiple processes including apoptosis by releasing the inducing factor: PARP. Natural compounds, in combination with conventional chemotherapy TMZ, are a powerful approach to improve the effectiveness of brain cancer treatment.

Quinonoids: Therapeutic Potential for Lung Cancer Treatment

Lung cancer is the leading cause of cancer-related deaths worldwide. Owing to its high incidence and mortality, the development and discovery of novel anticancer drugs is of great importance. In recent years, many breakthroughs have been achieved in the search for effective anticancer substances from natural products. Many anticancer drugs used clinically and proven to be effective are derived from natural products. Quinonoids, including naphthoquinones, phenanthrenequinones, benzoquinones, and anthraquinones, constitute a large group of natural bioactive compounds that widely exist in higher and lower plant species. Given that most of these compounds possess anticancer effects, they are applied in many cancer studies, especially in lung cancer research. They can promote apoptosis, induce autophagy, and inhibit proliferation, angiogenesis, and cell invasion and migration. Some drugs can enhance anticancer effects when combined with other drugs. Thus, quinonoids have broad application prospects in the treatment of lung cancer. Here, we summarize the previous studies on the antilung cancer activities of quinonoids together with their underlying mechanisms and analyze the common research targets with different effects so as to provide references for the discovery of quinonoids against lung cancer.

Role of HSP60/HSP10 in Lung Cancer: Simple Biomarkers or Leading Actors?

Cancers are one of the major challenges faced by modern medicine both because of their impact in terms of the amount of cases and of the ineffectiveness of therapies used today. A concrete support to the fight against them can be found in the analysis and understanding of the molecular mechanisms involving molecular chaperones. In particular, HSP60 and HSP10 seem to play an important role in carcinogenesis, supporting tumours in their proliferation, survival, and metastasis. Efforts must be directed toward finding ways to eliminate or block this "mistaken" chaperone. Therefore, the scientific community must develop therapeutic strategies that consider HSP60 and HSP10 as the possible target of an anti-tumoural treatment and not only as diagnostic biomarkers, since they contribute to the evolution of pre-cancerous respiratory pathologies in lung tumours. HSP60 acts at the mitochondrial, cytoplasmic, and extracellular levels in the development of cancer pathologies. The molecular mechanisms in which these chaperones are involved concern cell survival, the restoration of a condition of absence of replicative senescence, the promotion of pro-inflammatory environments, and an increase in the ability to form metastases. In this review, we will also present examples of interactions between HSP60 and HSP10 and different molecules and ways to exploit this knowledge in anticancer therapies for lung tumours. In order to improve not only chances for an earlier diagnosis but also treatments for patients suffering from this type of disease, chaperones must be considered as key agents in carcinogenesis and primary targets in therapeutics.

Aloe-emodin induces hepatotoxicity by the inhibition of multidrug resistance protein 2

BACKGROUND

Aloe-emodin (AE) is among the primary bioactive anthraquinones present in traditional Chinese medicinal plants such as Rheum palmatum L. Multidrug resistance protein 2 (ABCC2/ MRP2) is an important efflux transporter of substances associated with cellular oxidative stress. However, the effects of traditional Chinese medicine on this protein remain unclear.

PURPOSE

The aim of this research is to study the role of ABCC2 in AE-induced hepatotoxicity.

METHODS

The expression of ABCC2 protein and mRNA levels were analyzed by Western-Blotting and qRT-PCR, respectively. The intracellular oxidative stress caused by AE was evaluated by quantifying the levels of intracellular reactive oxygen species, malondialdehyde, glutathione reduced and oxidized glutathione. The levels of adenosine triphosphate, mitochondrial membrane potential and mitochondrial DNA were explored to evaluate the effects of AE on mitochondrial function. The effects of AE on cell apoptosis and cell cycle were detected by flow cytometry. To further clarify the key role of ABCC2 in AE induced cytotoxicity, we used pCI-neo-ABCC2 plasmid to over express ABCC2 protein, and small interfering RNA was used to knockdown ABCC2 in HepG2 cells. Additionally, we investigated the impact of AE on ABCC2 degradation pathway and the hepatotoxic effects of AE in mice.

RESULTS

AE was found to inhibit ABCC2 transport activity, downregulate ABCC2 expression and altered intracellular redox balance. Induction of oxidative stress resulted in depletion of intracellular glutathione reduced, mitochondria dysfunction and activation of apoptosis. ABCC2 overexpression significantly reduced AE-induced intracellular oxidative stress and cell death, which was enhanced by ABCC2 knockdown. Furthermore, AE was observed to promote ABCC2 degradation through induction of autophagy and hepatotoxicity was induced in mice by promoting ABCC2 degradation.

CONCLUSIONS

The inhibition of ABCC2 is a novel effect of AE that triggers oxidative stress and apoptosis. These findings are helpful in understanding the toxicological effects of AE-containing medicinal plants.

Aloe-emodin: A review of its pharmacology, toxicity, and pharmacokinetics

Aloe-emodin is a naturally anthraquinone derivative and an active ingredient of Chinese herbs, such as Cassia occidentalis, Rheum palmatum L., Aloe vera, and Polygonum multiflorum Thunb. Emerging evidence suggests that aloe-emodin exhibits many pharmacological effects, including anticancer, antivirus, anti-inflammatory, antibacterial, antiparasitic, neuroprotective, and hepatoprotective activities. These pharmacological properties lay the foundation for the treatment of various diseases, including influenza virus, inflammation, sepsis, Alzheimer's disease, glaucoma, malaria, liver fibrosis, psoriasis, Type 2 diabetes, growth disorders, and several types of cancers. However, an increasing number of published studies have reported adverse effects of aloe-emodin. The primary toxicity among these reports is hepatotoxicity and nephrotoxicity, which are of wide concern worldwide. Pharmacokinetic studies have demonstrated that aloe-emodin has a poor intestinal absorption, short elimination half-life, and low bioavailability. This review aims to provide a comprehensive summary of the pharmacology, toxicity, and pharmacokinetics of aloe-emodin reported to date with an emphasis on its biological properties and mechanisms of action.

Emodin promotes the arrest of human lymphoma Raji cell proliferation through the UHRF1‑DNMT3A‑∆Np73 pathways

Emodin is an active constituent found in the roots and rhizomes of numerous Chinese medicinal herbs. It exerts antitumor activity against Dalton's lymphoma in vivo, although the detailed mechanisms by which emodin induces apoptosis remains to be elucidated. The present study aimed to analyze the mechanisms underlying the response to emodin treatment. Using lymphoma Raji cells, an emodin‑induced cell proliferating inhibition model was first established, then flow cytometry, western blotting, reverse transcription‑quantitative polymerase chain reaction and luciferase reporter assay were performed. It was found that emodin decreased the percentage of Raji cell viability, induced apoptosis, and increased the activation of caspase 3, caspase 9 and poly (ADP‑ribose) polymerase through the downregulation of ubiquitin‑like protein containing PHD and RING domains 1 (UHRF1). The emodin‑induced downregulation of UHRF1 led to an increase in the level of DNA methyltransferase 3A, which in turn inhibited the activity of p73 promoter 2 and decreased the levels of NH2‑terminally truncated dominant‑negative p73. The treatment of Raji cells with emodin combined with doxorubicin led increased cell death of Raji cells, indicating that emodin may sensitize Raji cells to doxorubicin‑induced apoptosis.

Study on synthesis and bioactivity of biotinylated emodin

A novel compound biotinylated emodin was synthesized by a two-step acyl chloride method which connects the biotin to emodin with esterification reaction. The product was characterized with ultraviolet-visible spectrophotometry, fourier transform infrared and high-performance liquid chromatography tandem mass spectrometry techniques. Its antibacterial activity against Staphylococcus aureus CMCC 26003 was investigated, and the emodin- and biotinylated emodin-caused antibacterial mechanism was proposed. It was shown that the product was isolated and activity of emodin was remained. These results indicated that our study provides a kind of chemosynthesis method under mild conditions and a strong molecular tool for investigating the emodin-binding protein.

Aloe-emodin exerts a potent anticancer and immunomodulatory activity on BRAF-mutated human melanoma cells

Aim of this study was to extend the knowledge on the antineoplastic effect of aloe-emodin (AE), a natural hydroxyanthraquinone compound, both in metastatic human melanoma cell lines and in primary stem-like cells (melanospheres). Treatment with AE caused reduction of cell proliferation and induction of SK-MEL-28 and A375 cells differentiation, characterized by a marked increase of transamidating activity of transglutaminase whose expression remained unmodified. In vitro antimetastatic property of AE was evaluated by adhesion and Boyden chamber invasion assays. The effect of AE on melanoma cytokines/chemokines production was determined by a multiplex assay: interestingly AE showed an immunomodulatory activity through GM-CSF and IFN-γ production. We report also that AE significantly reduced the proliferation, stemness and invasive potential of melanospheres. Moreover, AE treatment significantly enhanced dabrafenib (a BRAF inhibitor) antiproliferative activity in BRAF mutant cell lines. Our results confirm that AE possesses remarkable antineoplastic properties against melanoma cells, indicating this anthraquinone as a promising agent for differentiation therapy of cancer, or as adjuvant in chemotherapy and targeted therapy. Further, its mechanisms of action support a potential efficacy of AE treatment to counteract resistance of BRAF-mutated melanoma cells to target therapy.

Potential antineoplastic effects of Aloe-emodin: a comprehensive review

Aloe-emodin (AE), a bioactive anthraquinone derived from both Aloe vera and Rheum officinale, has recently been demonstrated to have various pharmacological activities. With the widespread popularity of natural products, such as antineoplastic drugs, AE has attracted much attention due to its remarkable antineoplastic activity on multiple tumor cells involving multi-channel mechanisms, including the disruption of cell cycle, induction of apoptosis, anti-metastasis, antiangiogenic, and strengthening of immune function. Experimental data have revealed AE as a potentially potent anti-cancer candidate. Despite this, the pharmaceutical application of AE is still in a fledging period as most research has concentrated on the elucidation of the molecular mechanism of action of existing treatments, rather than the development of novel formulations. Therefore, the present review summarizes the potential toxicity, molecular mechanism, pharmacokinetic characteristics, and pharmaceutical development of AE as an antineoplastic agent. This is based on its physicochemical properties, in an attempt to encourage further research on AE as a potential anti-cancer agent.

Application of proteomics to determine the mechanism of action of traditional Chinese medicine remedies

ETHNOPHARMACOLOGICAL RELEVANCE

The rationale for using traditional Chinese medicine (TCM) is based on the experience that has been gained from its wide use over thousands of years. However, the mechanisms of action of many TCM are still unclear. Proteomics, which mainly characterizes protein functions, protein-protein interactions, and protein modification in tissues or animals, can be used to investigate signaling pathway perturbations in cells or the whole body. Proteomics has improved the discovery process of effective TCM compounds, and has helped to elucidate their possible mechanisms of action. Therefore, a systematic review of the application of proteomics on TCM research is of great importance and necessity. This review strives to describe the literature on the application of proteomics to elucidate the mechanism of action of TCM on various diseases, and provide the essential discussion on the further utilization of proteomics data to accelerate TCM research.

MATERIALS AND METHODS

Literature survey was performed via electronic search on Pubmed with keywords 'Proteomics' and 'Traditional Chinese Medicine'. The papers written in English were acquired and analyzed in this review.

RESULTS

This review mainly summarizes the application of proteomics to investigate TCM remedies for neuronal disease, cancer, cardiovascular disease, diabetes, and immunology-related disease.

CONCLUSIONS

Researchers have applied proteomics to study the mechanism of action of TCM and made substantial progresses. Further studies are required to determine the protein targets of the active compounds, analyze the mechanism of actions in patients, compare the clinical effects with western medicine.

Application of proteomics to identify the target molecules involved in Lonicera japonica-induced photokilling in human lung cancer CH27 cells

Background

The Lonicera japonica has been used as natural and healthy drink for its anti-inflammatory effect and pleasant odor in China and Taiwan.

Methods

2D electrophoresis was used to analyze the proteins involved in photoactivated Lonicera japonica-induced CH27 cell apoptosis. The fluorescent dyes MitoTracker Red CMXRos, calcein AM and JC-1 were used to elucidate mitochondrial function. The protein expression was performed by Western blotting. Fluorescent image of endoplasmic reticulum was accomplished by using ER-Tracker Green. This study used fluorescent dye CM-H₂DCFDA to detect intracellular generation of reactive oxygen species.

Results

The identified proteins can be classified into three major groups, which include proteins involved in mitochondrial function, cytoskeleton-related proteins and proteins associated with endoplasmic reticulum (ER) stress. Photoactivated Lonicera japonica caused a significant effect on the mitochondrial function and ER stress in CH27 cells. The reactive oxygen species producing was found to be involved in photoactivated Lonicera japonica-induced CH27 cell apoptosis.

Conclusion

Mitochondria and endoplasmic reticulum are the integral targets in photoactivated Lonicera japonica-induced CH27 cell apoptosis. We also demonstrated that ethyl acetate fraction of Lonicera japonica extracts caused photocytotoxicity in a dose-dependent manner in CH27 cells. This could explain the fact that the ethyl acetate fraction of Lonicera japonica extracts may contain compounds which exhibit the photosensitizing activity in CH27 cells.

Dihydroartemisinin-induced inhibition of proliferation in BEL-7402 cells: an analysis of the mitochondrial proteome

Artemisinin, the active ingredient of the Chinese medicinal herb Artemisia annua L., and its derivatives (ARTs) are currently widely used as anti-malarial drugs around the world. In this study, we found that dihydroartemisinin (DHA), one of the main active metabolites of ARTs, inhibited the proliferation of human hepatocarcinoma BEL-7402 cells in a concentration-dependent manner. To interpret the mechanisms involved, an analysis of the mitochondrial proteome was performed employing two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Seven mitochondrial proteins including fumarate hydratase, 60 kDa heat shock protein, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, two subunits of ATP synthase and NADPH:adrenodoxin oxidoreductase were identified to be differentially expressed between the control and DHA-treated groups. Our results indicate that the imbalance of energy metabolism induced by DHA may contribute, at least in part, to its anti-cancer potential in BEL-7402 cells.

Energy matters: mitochondrial proteomics for biomedicine

This review compiles results of medical relevance from mitochondrial proteomics, grouped either according to the type of disease - genetic or degenerative - or to the involved mechanism - oxidative stress or apoptosis. The findings are commented in the light of our current understanding of uniformity/variability in cell responses to different stimuli. Specificities in the conceptual and technical approaches to human mitochondrial proteomics are also outlined.

Proteomic analysis reveals ATP-dependent steps and chaperones involvement in luteolin-induced lung cancer CH27 cell apoptosis

The present study applied 2D electrophoresis to analyze the proteins involved in luteolin (50 microM)-induced CH27 cell apoptosis. We found 7 proteins to be markedly changed. According to the data of analysis of these protein spots, we hypothesized that ATP synthetic pathway and heat shock proteins were involved in luteolin-induced CH27 cell apoptosis. In this study, luteolin induced a significant change in intracellular ATP levels and mitochondrial activity of CH27 cells. Further experiments demonstrated that pretreatment with forskolin blocked the luteolin-induced cell death. P38 and heat shock protein 27 may be important participants in the luteolin-induced changes in organization of actin microfilaments in this study. In addition, endoplasmic reticulum stress is also important in the luteolin-induced CH27 cell apoptosis. Our findings suggested that the function of mitochondria and endoplasmic reticulum is the integral factor in luteolin-induced CH27 cell apoptosis.